endocrine system Flashcards
exocrine gland
secrete products directly into ducts
endocrine glands
secrete products (hormones) into blood and target effector organs
major exocrine glands
found in digestive system, sweat glands, salivary glands, milk ducts, subaceous glands, tears (lacrimal glands)
major endocrine glands
hypothalamus, anterior pituitary, posterior pituitary, thyroid, parathyroid, adrenal cortex and medulla, pancreas, gonads
major organ with endocrine and exocrine function
pancreas
exocrine portion of pancreas
digestive enzymes
endocrine portion of pancreas
insulin and glucagon
what are the exocrine and endocrine functions of the liver
exocrine: secretes bile
endocrine: secretes angiotensin
paracrine signaling
signaling acts on nerby cells
- heavily involved in embryonic differentiation
which type of signaling is thought to be associated with cancer
autocrine
juxtacrine singaling
cells must be in close contact for communication
merocrine cell
if cell releases secretions through exocytosis
merocrine cell
secretion via exoctyosis
merocrine cell
if cell releases secretions through exocytosis ec
eccrine glands
merocrine sweat glands
apocrine glands
release through membrane bound vesicles
- mammory and sweat
holocrine secretions
rupture of plasma membrane and releasing product
- subaceous glands
peptide hormones
amino acid based hormones that are polar and must have a membrane receptor
steriod hormones
nonpolar and derived from cholesterol
4 ring structure
can diffuse readily across plasma membarne and bind to dna
primary signal in peptide homrones
peptide hormone
why do hormones require transport proteins in the blood
because they are not soluble
nonspecific steroid transport protein
albumin
once in the cell what do steriod hormones bind to
nuclear receptors
major effect of steroid hormones in the cell
gene expression
preprohormones
early precursors of PEPTIDE hormones that are transferred to the rough ER to become prohormones
prohormones
inactive immediate precusors to peptide hormones
where are prohormones cleaved to become complete peptide hormones
golgi
steroid hormones are derived from what
cholesterol in smooth ER
are there intermediate stages of steriod hormone formation
no
only peptide hormones go through pre and pro stages
are peptide hormones soluble in blood
yes, this is why they do not need a transport protein like steroids
which type of hormone has more rapid effect? which one is the most long term
peptide and steroid respectively
typical functions of steroid hormomes
sex, salt, sugar
examples of steriods
aldosterone, cortisol, estrogen
amino acid derived hormones
small peptide hormones from 1 amino acid
ex: T3 and T4 are tyrosine deriviatives and are lipid soluble
catecholamines
hormone derived from tyrosine and are hydrophilic
- norepinephrine and epinephrine
what hormone is derived from tryptophan and is both lipid and water soluble
melatonin
tropic hormones
cause the release of downstream hormones
hypothalamus anterior pituitary adrenal axis
Crh –> acth –> cortisol
- cortisol inhibits CRH and ACTH
which hormone exhibits positive feedback
oxytocin during labor contractions
insulin
peptide hormone released by beta cells of pancreas that cause cell uptake of glucose and decrease BGL
- activate glucose transporters
what processes does insulin upregulate
glycolysis, glycogen synthesis, fatty acid synthesis
what processes does insulin inhibit
glycogenolysis, fatty acid degredation (lipolysis), fatty acid oxidation
glucagon
peptide hormone released by alpha cells of pancreas and is opposite of insulin
- released in response to low BGL and encourages release of glucose from cells into the blood
which processes does glucagon promote
glycogenolysis, and gluconeogenesis
what organ is responsible for gluconeogenesis
liver because it has glucose 6 phosphotase
what other hormones can increase BGL
cortisol and epinephrine
major hormones of calcium regulation
calcitonin and parathyroid hormone .;
what hormone is released in response to low blood calcium levels in order to raise it
PTH
how does PTH increase ca levels
by increasing osteoclast activity
what hormone is released to bring down blood calcium levels
calcitonin
how does calcitonin decrease blood calcium levels
inhibiting osteoclast activity
vitamin D
crucial for serum calcium and phosphate levels
calcitrol
active form of of vit D that affects calcium and phosphate levels
- similar finction to PTH
- increases calcium levels by increasing absorption of ca in gi tract
little fluid means
low blood pressure
low blood volume
increased blood osmolatiry
increased fluid
high bp
high blood volume
low blood osmolarity
which hormones respond to low blood volume
aldosterone and ADH
aldosterone
increases blood volume and blood pressure by increasing sodium absorption in the distal convuluted tubule and collecting duct which increases water absorption
adh/vasopressin
increases the permiability of the collecting duct to water and increases water absorption
reduces blood osmolarity wihtout changing solute concentration
where and when is ADH released
released from the posterior pituitary in response to low blood pressire and high plasma osmolarity
where and when is aldosterone released
released from the adrenal cortex in response to low blood pressure and is regulated by angiotensin system
renin
enzyme released from the kidneys that converts angiotensinogen into angiotensin 1
what is angiotensin 1 converted into
angiotensin 2 in the lungs
what is the immediate stimulus of aldosterone
angiotensin 2
main function of aldosterone
restores blood pressure (raises blood volume) and inhibits the release of renin
ANP
hormone that endocrine system uses to deal with excess blood volume
- opposite of aldosterone
- decreases sodium reabsorption in the distal convuluted tubule and collecting duct `
ANP
hormone that endocrine system uses to deal with excess blood volume
- opposite of aldosterone
- decreases sodium reabsorption in the distal convuluted tubule and collecting duct
what hormone inhibits aldosterone release
ANP
cortisol
long term stress
where is cortisol released from
adrenal cortex
glucocorticoids
class of horones from adrenal cortex
what metabolic pathway does cortisol stimulate
gluconeogensis and antagonist to insulin
epinephrine
short term stress response homrone that increase blood glucose levels
what metabolic pathways does epinephrine induce
glycogenolysis, gluconeogeneiss, glucagon release
what is norepinephrine
catacholamine synthesized from tryosine that can be a neurotransmitter or a hromone
function of t3 and t4
increase basal metabolic rate
- released in response to TSH from AP
hypothroyid
insufficient thyroid hormones
fatigue, weight gain, iodine deficiency, , decrease body temp
hyperthryoid
excess t3 and t4 with weight loss, hunger, insomnia, increased body temp
where are esteogen and testosterone produced
gonads: ovaries and testes
progesterone
prepares uterus for implantation and maintains it throughout pregnancy
lutenzing hormone
stimulates the release of estrogen and testosterone
luteal surge
LH stimulates the release of estrogen leading to ovulation
FSH
ovarian follicle stimulation and spermatogensis
HcG
maintains corpus luteum during pregnancy and causes it to secrete progesterone
prolactin
acts on mammory glands to produce milk
tropic hormones of anterior pituitary
TSH, ACTH, LH, FSH, GH
FLaTPiG
tropic hormones of hypothalamus
GnRH, TRH, CRH, GHRH
is human chroionic gonadotropin a releasing hormone
yes, causes lh to maintain corpus luteum
what are the effects of aldosterone
increased na absorption in DCT and blood volume/ pressure increases
effects of ADH
increased water absorption in collecting duct to increase fluid levels
effects of ANP
decreased NA absorption in DCT and blood volume decreases
hypothalamus
bridge between nervous and endocrine systems
- located in forebrain
what connects the hypothamus and the anterior pituitary
hypopheseal portal system
- hormones transported
similarity of hormones between anterior and posterior pituitary
ALL HORMONES ARE PEPTIDE
what cells in males does LH stimulate
interstitial cells of ledig to secrete tesosterone
what in females does LH induce
ovarian estrogen production
funciton of ACTH
induces production of glucocorticoids and mineralcorticoids in adrenal cortex
nontropic hormones of anterior pituitary
endorphins, growht hormone, prolactin
hormones of posterior pituitary
ADH/ vasopressin and oxytocin
ADH major function
secreted during dehydration to increase fluid volume and blood pressure
hormones of thyroid
t3/t4 and calcitonin
adrenal gland
divided into cortex and medulla
adrenal cortex
secrete corticosterioids like cortisol
- can be mineralcorticoids or glucocorticoids
adrenal medulla
epinephrine/norepinephrine
alpha cells of pancreas
glucagon secretion in response to low BGL
beta cells of pancreas
secrete insulin in response to high BGL
delta cells of pancreas
secrete somatostatin (slow rate of digesion)
pineal glands
secrete melatonin
hormone of heart
ANP , decrease blood volume and decrease pressure
thymus
t cells of adaptive immunity mature
